FCS errors on NIC

[Tim Killinger]

I researching versy slow FTP transfer rates on our new 11.0 UX. lanadmin reports the following. A bunch of FCS errors. I suspect from a previous thread that I need to disable autonegotiate.

Thanks everyone... these forums are lifesavers!

What are FCS errors?

Thanks!


LAN INTERFACE STATUS DISPLAY
Wed, Jan 8,2003 09:15:50

PPA Number = 0
Description = lan0 Hewlett-Packard 10/100 TX Full-Duplex TT
= 1500
Type (value) = ethernet-csmacd(6)
MTU Size = 1500
Speed = 100000000
Station Address = 0x306e06a63c
Administration Status (value) = up(1)
Operation Status (value) = up(1)
Last Change = 685
Inbound Octets = 830703696
Inbound Unicast Packets = 315469
Inbound Non-Unicast Packets = 5439483
Inbound Discards = 115
Inbound Errors = 106083
Inbound Unknown Protocols = 4579833
Outbound Octets = 23536398
Outbound Unicast Packets = 290597
Outbound Non-Unicast Packets = 55781
Outbound Discards = 0
Outbound Errors = 0
Outbound Queue Length = 0
Specific = 655367

Press to continue


Ethernet-like Statistics Group

Index = 1
Alignment Errors = 726
FCS Errors = 106079
Single Collision Frames = 0
Multiple Collision Frames = 0
Deferred Transmissions = 0
Late Collisions = 0
Excessive Collisions = 0
Internal MAC Transmit Errors = 0
Carrier Sense Errors = 0
Frames Too Long = 4
Internal MAC Receive Errors = 0


LAN Interface test mode. LAN Interface PPA Number = 0

clear = Clear statistics registers
display = Display LAN Interface status and statistics registers
end = End LAN Interface Administration, return to Test Selection
menu = Display this menu
ppa = PPA Number of the LAN Interface
quit = Terminate the Administration, return to shell
reset = Reset LAN Interface to execute its selftest
specific = Go to Driver specific menu

Enter c

[Tim Killinger]

I'll close this out

[rick jones]

FCS == Frame Check Sequence. IIRC a 32-bit CRC (Cyclic Redundancy Check) covering Ethernet frames. Basically, an Ethernet checksum.

FCS errors can mean flaky hardware, or a duplex mismatch.

Autoneg would have to be disabled if the switch port is hard-coded, but the lanadmin stuff showd the link to be in full-duplex, and IIRC since there is no "AUTO" in the description string I'm guessing that the NIC is already being hard-coded.

Hardcoding means that autoneg by the other side will not work. That you have FCS errors suggests that either the switch port is set to auto, or hard-coded to half.

I would try auto on both sides first and see if that works. If that does not, then hardcode both sides to the same value, and I would suggest that all the ports on the switch be hardcoded to that value and all the NICs in other systems to that value as well. Otherwise, someone comes-in and "cleans-up" the wiring closet and all hell breaks loose. (Which is why I prefer to use auto unless I _know_ beyond a shadow of a doubt that it 1, does not work, and 2, cannot be made to work through either a patch, switch firmware update, or replacing the broken switch with something that works.

[Steven E. Protter]

There are patches for certain NIC cards that must be installed to duplex properly.

I had some issues in this regard on a D380 box.

Steve